zig comptime return

example.zig

fn makeToken(comptime id: Identifier, comptime data: []const u8) []const u8 {
    comptime {
        assert(data.len < longFormMin);

        return makeIdentifier(id) ++ []u8{
            @truncate(u8, data.len),
        } ++ data;
    }
}

fn makeIdentifier(comptime id: Identifier) []const u8 {
    comptime {
        const number = id.tag.number();

        assert(number < multipartNumber);

        return []u8{
            u8(@enumToInt(id.tag.class()))<<6 | u8(@enumToInt(id.encoding))<<5 | @truncate(u8, number),
        };
    }
}

test "bloop" {
    comptime const data = makeToken(A, []u8{0}); // error here
}